With the growing popularity of smart home, a traditional lighting switch needs to be upgraded as a smart lighting switch. However, since most ordinary families employ single live wire cabling, the technology for drawing power using a single live wire is required during replacing the traditional lighting switch by the smart lighting switch.
Current smart lighting switches may be divided into an electronic disconnection type and a complete disconnection type. The electronic disconnection means that aperiodic and proper functional characteristics are achieved by relying on a semiconductor switching device. The complete disconnection means that the proper functionality is achieved by relying on a distance between open contacts, which is comparable to a basic insulation. In a case where the technology for drawing power using a single live wire is applied to the smart lighting switch of the electronic disconnection type, when the switch is off, problems such as flashing or slightly brightness may occur after the lamp is turned off due to the existence of leakage current, and the security is poor.
In the case where the technology for drawing power using a single live wire is applied to the smart lighting switch of the complete disconnection type, although no leakage current exists in the circuit when the switch is off, the power drawing circuit using a single live wire may be only applied to one way of switch. If multiple ways of switch are required, each way of switch is required to have respective power drawing circuits using a single live wire. In addition, the power drawing circuit using a single live wire corresponding to each circuit needs to be output in parallel after being isolated at an output terminal. The cost is relatively high.
It should be noted that, the above information disclosed in this section is only for helping understanding background of the present disclosure. Therefore, it may include information that does not constitute prior art known by those skilled in the art.